<!doctype html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>js示例4-10-14</title>
	<script>
		var stringA="This is a student.";
		var stringB="s";
		alert(stringA.lastIndexOf(stringB));
		
	</script>
</head>
<body>
	
</body>
</html>